The usingSRTP flag isn't actually meant to be checked at the points you've
added. It disrupts some of the functionality.

Yes, we discussed this with Romain earlier today. This is simply a
temporary fix that I committed in order to make sure that we don't
access zrtp-related code anywhere because it was breaking standard
telephony.

We will of course get rid of it as soon as you are ready with a working
and relatively stable version.